sorry about the delay in my response to this thread......im just a lil fish in this new jet ski world.....but as for your back....everything they are saying as for excercises is totally correct, but the number one thing we can all do to prevent back pains is easy......Just Stretch before you ride.....i swear by it......next time you go out, spend about a good 15 minutes stretching all of your muscles and really get them loose.....youll see that you will last longer, and the aches in the lower back especially will be gone. I find that if i just get excited, and hop on my ski and hit the water, the cool water tightens up my muscles and then all the hopping around pulls em.....kinda like a conflict and before you know i gotta aching back......just my two cents....hope it helps.......
Jay-Are